• With the increasing use of the internet, there is also increase in threats to the computers.

• The main objectives of these threats is to destroy the data and to steal the vital information stored
in computers.

Viruses

• A computer virus is a program usually hidden within another simple program.

• These programs destroy data and perform other malicious actions by producing copies of itself and inserting them into other programs or files.

• These are created with a specific target in mind such as data theft or destruction of software.

• Viruses are of different types but a common virus is macro virus.

• Macro Virus: It is series of programming steps that are stored in a single location.

→ These can be embedded in the program files.

→ These viruses created with the intention of fooling the user can deceive them in sharing confidential information.

→ The virus using macro files are most popular as they are:
♠ Easy to write.
♠ Can infect more people faster as they exchange documents and data frequently
♠ Can easily infect any computer capable of running Office and Internet.

→ Macro viruses modify registries, forward copies of it through emails, look for passwords, copy documents, and infect other programs.

→ Examples of Macro Viruses: Wazzo, W97M etc.

Worms

• Worms are computer programs that replicate copies of themselves.

• They are very similar to viruses however many difference are present between them.

• Difference between Worms and Viruses
→ Viruses often, but not always, contain some functionality that will interfere with the normal
use of a computer or a program however, worms exist as separate entities; they do not attach themselves to other files or programs.

• Some examples of the worst Worms that impacted we are:

→ Jerusalem is one of the earliest worms that spread in 1987. It used to delete files that were executed on each Friday the 13th.

→ In 1991, thousands of machines running MS-DOS were hit by a new worm, Michelangelo. The virus would overwrite the hard disk or change the master boot record of infected hosts.

• It is never possible to completely stop the Spam email because Internet is a public platform. However precaution can be taken while looking at an unknown email addresses.Hackers and Crackers

• Hackers and crackers are the software programmers who use dubious ways to get control over your computer and systems.

• Their main objective is to gain control over a computer so that they can get the sensitive confidential information.

• They use information against you by stealing money, personal data, pictures, bank details and government military information, so on and so forth.

• Hackers were the gifted programmers who gain access to the systems or network to show case the security loopholes to the administrators.

• Crackers have an end goal of destroying data and network for personal monetary gains.

AntiVirus Tools

• Anti Virus tools are the software programs that help us detect the virus in emails or files and hence protect our computers.

• These tools can detect virus, worms, Trojans as well as spyware and adware.

• They block us from visiting unsafe websites, and also downloading unsafe programs from such websites.

• They protect us from identity thefts and threats from phishing websites.

• Examples are Norton, Mcafee, K7, Quickheal etc.

Data Backup and Security

• The basic principal on data back up is very simple, just make another copy of the data and keep it elsewhere than on the same computer.

• This guarantees that once the data on your computer gets corrupted due to a threat, you can reload the data again on your computer once it has been rectified.

• We can use external hard drives and smart devices are to back up the data.

• Some guideing principles to use the computers securely:

→ Using Security software such as Norton antivirus, Symantec etc.
→ Never share passwords
→ Beware of email attachments form unknown sources
→ Do not randomly download material from websites which has not been checked for security
→ Never propagate hoax or chain emails
→ Always logout your laptop or computer
→ Restrict remote access
→ Frequently back up important data and files
→ Use encryption or sites that use encrypted data